Railway signaling system



May 3, 1938. R. A. SHEETS ET AL.

RAILWAY SIGNALING SYSTEM Filed May 11, 1935 INVENTOR5 RAfiheeTs" and 5. E. Noble THEIR ATTORNEY Patented May 3, 1938 PATENT OFFICE RAILWAY SIGNALING SYSTEM Robert A. Sheets, Oak Park, and Stanley E. Noble, Lake Forest, Ill., assignorsto General Railway Signal Company, Rochester, N. Y.

Application May 11, 1935, Serial No. 20,996

3 Claims.

This invention relates to railway signaling systems, and more particularly to a means for increasing the safety of train operation in the event of a failure of an incandescent lamp employed 5 in railway light signals.

The incandescent lamps used in railway light signals are usually replaced after what has been found to be their average length of life, but it is found that the life of any one lamp is very indefinite and many times certain ones of the lamps burn out long before their average life has expired. Consequently when such a lamp failure occurs, the engineer of a passing train is liable, especially at night, to entirely overlook and run past that signal into what may be a'dangerous section of track.

In view of the above and other considerations, it is proposed in accordance with the present invention to provide a means for eliminating the possibility of an engineers overlooking a signal having a burned out lamp by causing the signal in the rear thereof to display a restrictive indication regardless of traffic conditions, thereby causing the engineer to expect an abnormal condition at the signal at which the lamp failure occurs. More specifically, it is proposed to provide a means for detecting a failure of an incandescent lamp, which means affects the usual block signaling circuits in a manner to provide a caution (or a danger) indication at the signal in the rear thereof.

Other objects, purposes and characteristic features of the present invention will appear as the. description thereof progresses, during which references will be made to the accompanying drawing, in which:

Fig. 1 shows in a diagrammatic and conventional manner one form of the present invention applied to a conventional railway signaling sys- 4,0 tern.

Fig. 2 shows also in a diagrammatic and conventional manner a modification that can be made in the form of the present invention shown in Fig. l.

45 In Fig. l of the accompanying drawing, a section of railway track is diagrammatically illustrated as divided into track sections by insulating joints 3, a track relay TR being associated with each section which is. of course energized 50 over the usual track circuit which has not been shown in detail. Inasmuch as the railway signaling apparatus associated with any one of these sections is duplicated for every other section, the like parts thereof are identified by like reference 55 characters with distinguishing exponents.

A color light signal S is diagrammatically shown at the entrance of each of these sections, which signal S governs traffic from left to right therethrough. A signal mechanismSM is shown diagrammatically for each of the signals S which 5 may be of the type shown and described in the prior application of O. S. Field, Ser. No. 470,056 filed July 23, 1930. This mechanism may be briefly described as a rotor biased to a center position and operated therefrom in a clockwise or 10 a counter-clockwise direction according to the irection of current in an operating winding W, the rotor being herein illustrated in a clockwise rotated position in response to the normal direction of current in winding W wherein a green 15 glass spectacle attached thereto is positioned at the focal point of an incandescent lamp L to display a green signal indication. This rotor also carries a yellow spectacle Y which is operated to a position in front of the same lamp L to display a yellow signal indication in response to the reverse direction of current, in winding W, and likewise a red spectacle R is operated to a position in front of lamp L to display a red signal indication when the winding W is deenergized.

The signal mechanism SM is also provided with contacts 4 and 5 operated by the rotor in an obvious manner, which contacts control the flow of current to a control relay CR from a battery B. The relay CR in turn controls the direction of 3 current in the operating winding W of the signal mechanism SM associated with the rear adjacent track section. The lamp L of each signal mechanism is energized from the battery B by current flowing through a suitable series relay SR so that normally the armature of relay SR is attracted by the energizing current of lamp L, but in case the filament thereof burns out, the armature of relay SR is released.

The above apparatus of the present system is illustrated in its normal clear condition, wherein relay CR. is energized over a circuit from the upper terminal of battery B, wire 6, contact 4 operated to its right-hand position, front contact 3 of relay SR, through the windings of relay CR to the lower terminal of battery B. It will be clear that relay GR is likewise energized when the signal mechanism is rotated in a counterclockwise direction to display a caution or yellow indication over a circuit from the upper terminal 50 of battery B, wire 6, contact 5 in its operated or left-hand position, contact 4 in its released or left-hand position, front contact 8 of relay SR, through the windings of relay CR. to the lower terminal of battery B.

The energization of relay CR causes current to flow in winding W of the rear adjacent signal mechanism SM in a normal direction over a circuit from the upper terminal of battery B, through front contact In of relay CR, line wire ll, through the operating winding W of the rear adjacent signal mechanism, front contact I2 of its associated track relay, line wire l3, front contact I l of control relay CR and back to the lower terminal of battery B. However when the signal mechanism SM displays a danger or red indication, the contacts 4 and 5 are both released which obviously deenergizes relay CR and reverses the direction of current in winding W of the next signal mechanism in the rear in an obvious manner by the dropping of the polechanging contacts Ill and M of relay CR, thereby causing the display of a caution indication at the rear adjacent signal.

Now considering that the filament of lamp L burns out, the armature of relay SR releases thereby opening the energizing circuit for relay CR at front contact 8 The release of relay CR then causes a reverse direction of current to flow in operating winding W of signal mechanism SM as just described, which effects the display of a caution indication at signal S This caution indication in this case may not be warranted by a stop indication at signal S as is usually the case, but rather it now serves the purpose of insuring that the engineer of a passing train may be alert and not run past the next signal which is dark due to the burned out signal lamp, and consequently he may be governed by the rules determining his procedure through the section governed by this dark signal.

In some applications of the present invention, it may m desirable to provide a danger indication rather than caution at the rear of a signal having a burned out lamp, and in this case the system in Fig. 1 may be modified as shown in Fig. 2. In Fig. 2, a front contact H of relay SR is included in the line wire I3 so that the release of relay SR due to the burning out of lamp L deenergizes the operating winding W of the rear adjacent signal mechanism SM This arrangement then causes the display of a danger or red indication at signal S so that the engineer of a passing train proceeds under rules governing such indication through both the track sections governed by signals S and S A railway signaling system has thus been provided which eliminates in a very simple manner the possibility of an engineer overlooking and overrunning past a signal having a burned out signal lamp filament. In other words, the present invention provides a relay normally energized in response to the flow of current through the lamp filament, which relay releases when the lamp filament burns out to effect the display of either a caution or a danger indication as desired at the signal next in the rear thereof. In this manner, the engineer must proceed under the restrictions determined by this caution or danger indication until a signal displaying a clear indication is reached, thereby insuring that due caution will be used in passing through a track section where a lamp failure prevents the display of a signal indication.

In describing the present invention, attention has been directed to two specific embodiments thereof without attempting to point out the various alternate or optional features of construction, or the difierent organizations or combinations that may be employed. For example, the present arrangement may be used in a railway signaling system employing separate signal units for each indication by employing the relays SR in series with the common portion of the energizing circuit for all of the signal lamps thereof, this and other modifications being within the ability of anyone skilled in the railway signaling art.

In other words the particular embodiments of the present invention have been selected to facilitate in the disclosure thereof rather than to limit the number of forms which it may assume.

What we claim is:

1. In a railway signaling system, spaced signals each having an incandescent lamp, a control line circuit for each signal normally energized to effect the display of a clear indication, a check light relay at each signal connected in series with the incandescent lamp, automatic means for de-energizing each line circuit in accordance with trafiic conditions to effect the display of a danger indication at the associated signal, and means for deenergizing each line circuit to eifect the display of a danger indication at the associated signal by the de-energization of said check light relay at the forward adjacent signal.

2. In a railway signaling system, in combination, spaced signals each having an incandescent lamp, a polarized line circuit for controlling the indication displayed by each signal, a filament check relay at each signal connected in series with a source of energy and the signal lamp filament, a control relay for each signal controlled by contacts of its signal and in turn connected to pole change the line circuit to the signal to the rear, and a front point of the check relay in the energizing circuit of the control relay.

3. In a railway signaling system, in combina-' tion, spaced signals each having an incandescent lamp, a polarized line circuit for controlling the indication displayed by each signal, a filament check relay at each signal connected in series with a source of energy and the signal lamp filament, a control relay for each signal controlled by contacts of its signal and in turn connected to pole change the line circuit to the signal to the rear, and a front contact of the. check relay in the line circuit to the signal to the rear.

STANLEY E. NOBLE. ROBERT A. SHEETS.

DISCLAIMER 2,115,979.Robert A. Sheets, Oak Park, and Stanley E. Noble, Lake Forest, Ill. RAILWAY SIGNALING SYSTEM. Patent dated May 3, 1938. Disclaimer filed May 17, 1939, by the assignee, General Railway Signal Company.

Hereby enters this disclaimer by disclaiming from claims 2 and 3 any system of railway signalling, except wherein the polarized line circuit causes a clear signal to be displayed by its signa when energized by current of one polarity, causes a caution signal to be displayed by its signa when energized by current of reverse polarity and causes its signa to display a danger indication each time said polarized line circuit is opened.

[Ofiicial Gazette Jane 13, 1939.] 

